In the developing chick embryo tibia type X collagen is synthesized by chondrocytes from regions of hypertrophy and not by chondrocytes from other regions (Capasso, O., G. Tajana, and R. Cancedda, 1984, Mol. Cell. Biol. 4:1163-1168; Schmid, T. M., and T. F. Linsenmayer, 1985, Dev. Biol. 107:375381). To investigate further the relationship between differentiation of endochondral chondrocytes and...